NASA's New Horizons Spacecraft Is On Pluto's Doorstep, Will Awaken on Saturday

NASA's New Horizons spacecraft is approaching Pluto, after a historic mission in which it traveled over three billion miles from Earth to the former ninth planet. On Saturday, December 6, the craft will awaken from the last of 18 hibernation periods in order to begin studying the dwarf planet.

NASA said in a statement, "After almost nine years of flight, we are literally on Pluto's doorstep, on schedule, in good health, and on course."

[Credit: NASA/Alex Parker]

Once New Horizons wakes up, it will begin five weeks of "pregame" tests of operations before the actual Pluto encounter on January 15.

"New Horizons is healthy and cruising quietly through deep space — nearly three billion miles from home — but its rest is nearly over. It's time for New Horizons to wake up, get to work, and start making history," Alice Bowman, New Horizons mission operations manager, said in a statement.

New Horizons left Earth in 2006, and only took a few hours to pass through the Moon's orbit. It reached Jupiter's gravity a year later, at which point scientists on Earth used that gravitational pull to increase the spacecraft's speed, which decreased the journey time by three years. Nine years later, New Horizons is nearly ready to begin observing the elusive Pluto.

[Credit: NASA/Johns Hopkins University]

Like many NASA missions, the New Horizons mission is expected to help scientists formulate hypotheses about early planet formation. But prior to the more complex theories, basic observations about Pluto will be taken, because the scientific community knows very little about it. Pluto is so small and so far away (15,000 times farther than our moon), the most advanced telescopes weren't able to discern any details about the dwarf planet until very recently, certainly after New Horizons left on its mission. Years also pass very differently there, which adds a further wrinkle; 248 years pass on Earth for every one year that passes on Pluto, which has made it difficult to map its orbit around the Sun.

To watch a live countdown to NASA's New Horizons Pluto Encounter, click here.